Elevator



May 20, 1958 w. BECK 2,835,345

ELEVATOR Filed Sept 14 1954 3 Sheets-Sheet 1 49 K i" 1 ML 1. x4 I J]IIHIII 3 3 W. BECK ELEVATOR May 20, 1958 5 Sheets-Sheet 2 Filed Sept.14, 1954 a MW M E CHAN/SM WEIGH 71E D FLA TFORM M y 1958 w. BECK2,835,345

ELEVATOR Filed Sept. 14, 1954 5 Sheets-Sheet 3 GUIDES 27L o o near/x1;PLATFORM CAR LIGHTS 2 53 ELEVATOR Walter Beck, Rock Island, 11].,assignor, by mesne assignments, to Montgomery Elevator Company, acorporation of Delaware Application September 14, 1954, Serial No.455,876

7 Claims. (Cl. 187---17) This invention relates to an elevator mechanismfor installation in locations where it is impractical to mount theoperating machinery for the elevator at the top of the shaft. It isparticularly. adapted for use in television or radio broadcast towers,although it may also be employed where similar problems are encountered.

The extreme normal range of a television transmitter is determined bythe height of the tower from which the signals are beamed, and for thisreason in hilly country a television broadcast tower will ordinarily belocated on a convenient ridge so as to increase the range of thestation, and the same result is achieved in the big cities by locatingthe television antennae on the top of tall buildings.

In flat country where there are no skyscrapers upon which televisionantennae may be mounted the range of a station can be increased only bybuilding an extremely high broadcast tower. Consequently, in the plainsstates television broadcast towers which are several hundred feet inheight are coming into use; and there are towers planned for parts ofthe southwest which are expected to be anywhere from a thousand tofifteen hundred feet high. This makes an elevator absolutely essentialto the maintenance of the upper parts of the tower, and work on theaircraft warning signal lights which are es sential on all suchstructures.

The construction of television towers is such that no conventionalelevator mechanism can practically be in stalled in such a tower;because the motor and drive pulley are at the top of the shaftway, andthe cables from which the elevator cage is suspended hang in a largeloop from the drive pulley with the cage on one side of the loop and acounterweight on the opposite side so that there is approximately evenweight on the two sides and the elevator motor may drive the elevatorcage in either direction with equal ease. The counterweight is essentialto provide balanced thrust in both directions on the drive pulley. Thisputs a very heavy load at the top of the shaftway, and makes itnecessary to do the majority of maintenance work at the top of theshaftway. No such arrangement could be employed in a broadcast towerwhich is several hundred feet high because the towers are very slenderand are supported by guy cables, and mounting of the heavy elevatordrive. mechanism at the top of the tower would throw a tremendous strainupon the cables as well as the entire tower structure. Furthermore, thetop of the tower is ordinarily quite open, and a housing for the drivemechanism would add further undesirable weight. Likewise, the space isvery restricted, and service work would be very difiicult.

In accordance with the present invention an idler pulley is placed atthe top of the shaftway, and the elevator drive pulley and motor aremounted upon a platform which is suspended from the bottom of theelevator cable, the cage being mounted at the two ends of the cable sothat it may run up and down between the sus- United States Patent2,835.3 Patented May 2t), 1938 pended, machinery weighted platform andthe idler pulley at the top of the shaftway. The weighted platformsuspended at the bottom of the cable provides ample friction between thedrive pulley and the cable to obtain it a positive drive withoutslippage, so that a counterweight may be eliminated. The elevatorshaftway may be provided with conventional vertical guide rails whichpermit the elevator cage to have all normal safety devices, and theweighted platform may be mounted to ride up and down a short distancebetween the lower ends of the guide rails to eliminate any problemsarising from cable stretch or changes in cable length and tower heightdue to temperature variations. The variations in cable length and towerheight due to temperature changes in a climate such as that found in thesouthwest of the United States may be eight or nine inches per thousandfeet of height.

Ordinarily the maintenance work necessary on a television broadcasttower can be performed by one man, or at the most, two; so the elevatorcage may be made quite small and light. A cage having a three footsquare platform is ample, and by using principally aluminum constructionthe total weight of the cage need be only five or six hundred pounds.Adequate friction on the elevator cable may be maintained by a machineryplatform having a total weight of about forty-eight hundred betweenguide rollers which may conveniently be mounted on the elevator cageitself to hold the cable away from the cage. Likewise, conventionalelevator mechanisms have a flexible control cable which connects thecontrol panel in the elevator cage electrically with the controls forthe elevator drive mechanism. Ordinarily the control cable is not undertension, so that it is particularly susceptible to wind deflection. Inparticular, the governor rope which normally hangs loose below theelevator cage could very easily be blown out of the shaftway and caughtin the tower framework. Thus,

make them substantially immovable.

the governor rope is also held in place by suitable rollers; and thecontrol cable is replaced by a series of parallel trolley wiresextending the length of the shaftway which may be supported at as closeintervals as is necessary to Electrical communication between thecontrol panel in the cage and the trolley wires is provided byconventional trolley shoes or rollers on the side of the cage.

The invention is illustrated in a preferred embodiment in theaccompanying drawings in which:

Fig. 1 is an elevational view of a broadcast tower provided withelevator mechanism constructed in accordance with the present invention;

Fig. 2 is a view similar to Fig. l, drawn to a larger scale, with thecenter portion of the tower broken away;

Fig. 3 is a section 011 an enlarged scale taken as indicated along theline 33 of Fig. 1;

Fig. 4 is a section on an enlarged scale taken as indi cated along theline 4-4 of Fig. 1;

Fig. 5 is a schematic view of an elevator mechanism constructed inaccordance with the present invention;

Fig. 6 is a schematic view of a normal high rise elevator mechanism;

Fig. 7 is a fragmentary elevational view of the upward travel limitcontrol trolley wire and associated trolley; and

Fig. 8 is a control circuit diagram.

Referring to the drawings in greater detail, and referring first toFigs. 1 and 2, a television broadcast tower it) is shown as consistingof the customary open girder construction, As seen in Figs. 3 and 4-,suitable cross. members it are provided at intervals within the broadcast tower framework in alignment with horizontal frame members l2 toreceive brackets 13 for longitudinal mounting plates 14 on which aremounted the guide rails 15 of the elevator shaftway. As best seen inFigs. 1 and 2, the mounting plates 14 and guide rails 15 ex tend attheir lower ends into a closed housing 16 at the bottom of the shaftway.

At the top of the tower is a pair of parallel girders l? which, as seenin Fig. 3, support pillow blocks 18 for a grooved idler pulley it? whichis journalled in the pillow blocks. An elevator cable it is trained overthe idler pulley l9 and has its ends secured to an elevator cage,indicated generally at 21, so that movement of the cable 20 over thepulley 19 may raise or lower the cage.

As seen in Figs. 2 and 4, platform 22 in the housing 16 has a base 23 onwhich is mounted an electric elevator motor 24 and gear case 25 having agrooved drive pulley as one end of the shaft for which is supported in abearing block 2'7. The elevator cable 2:3 passes around the grooveddrive pulley 26 so that the platform 22 is suspended from the cable. Theplatform: has recesses 28 provided with guide shoes 29 to receive theguide rails 15, so that the platform 22 may ride up and down in thehousing 16 to compensate for tower stretch or shinkage and cable stretchor shrinkage With temperature changes, and yet the platform is guidedagainst lateral shitting. The total weight of the platform 22 andmechanism supported thereon is sullicient to provide the necessaryfrictional engagement between the elevator cable 2d and the drive pulley26; and if the normal weight of the platform and machinery isinsufilcient, additional weights may be added as needed. The idlerpulley 19 and drive pulley 26 are shown as single should also be mountedbetween guide rollers similar to the guide rollers 37.

Control of the elevator may be accomplished by conventional controlswhich are illustrated diagrammatically .in Fig. 8. in ordinary elevatorconstruction the cable which connects a control panel in the elevatorcar with the elevator control mechanism at the motor hangs free in alarge loop below the elevator cage, and extends upwardly along the sideof the shaftway to the control panel adjacent the driving mechanism uponwhich are mounted the various relays and switches of the control system.Any loose cable of the above described character would be completelyimpractical in an open shaftway .such as that here contemplated, becausethe loose loo of cable could very easily be blown outside the cage.shaftway so that they may be anchored at whatever intervals arenecessary to prevent them from being serious- 1y deflected by wind. Aseries of trolley members 37a to 42a are mounted on the elevator cage toride respectively on the trolleys 37 to 42; and as seen in Fig. 7,

which illustrates the trolley 4 in, each of the trolleys .38 to up relay48, down relay and t. rough trol grooved, so that the elevator cage 21is supported by a single cable strand. cables might be used as is morecommon in elevator construction.

The elevator cage 21 is of generally conventional construction, in thatit has a lifting beam 31 upright side beams 31, and a base beam 32 uponwhich the platform 33 of the cage is mounted. As best seen in Pig. 2,the ends of the cable are secured, respectively, to the lifting beam 30and base beam 32. The platform 33 for the cage is of very smalldimensionsfor example, three feet square, and the cage is constructed oflightweight metals such as aluminum so as to reduce its weight tominimum. An adequate three foot square cage having enclosed sides 34-aud a seven foot high door opening 35 may have a weight as low as sixhundred to eight hundred pounds and a capacity of six hundred pounds,which is ample to carry one or two maintenance men and any equipmentthey would normally require for working on the upper levels of abroadcast tower. Extending rearwardly from one of the side beams 31 is abracket 36 at the end of which is mounted a pair of guide rollers 37between which the free side of the cable 20 is guided so that it doesnot slap against the cage 21 or the framework of the tower whensubjected to high winds to which it is exposed due to the open shaftwayconstruction. The elevator may also be equipped with a conventionalgovernor (not shown) which automatically sets safety brake shoes on theelevator car 21' into frictional engagement with the guide rails 15 ifthe elevator exceeds a predetermined maximum safe speed. This isstandard equipment and is not here shown. It is mentioned only becausethe governor rope (not shown) is ordinarily not under any substantialtension, and

However, it is obvious that several may conveniently consist of aparallelogram linkage 43 provided with a tension spring 43a which tendsto extend the linkage so as to hold a trolley wheel 44 in firm contactwith the trolley wire.

The trolley wire 37 furnishes a main control wire, which communicatesthrough trolley 37:: with the usual safety switches on the car, such,for example, as a normally closed safety switch t5, a gate switch 4-6and'a stop switch 57, through which the circuits pass through trolleywire ley wires 39 and ill and trolleys 39a and iller, respectively, to""up and down push buttons and 53. Car lights 52 and 53 may be wiredthrough a snap switch 54. The up" control circuit is completed throughup trolley 411a and '--\trolley wire 41, the upper end portion 55 ofwhich is sheathed with insulation so that if the car overruns thesheathed portion provides safety device which breaks the up circuit atthe trolley ila and stops the cage. The separate down trolley wire a2and trolley 42a permit l the cage to be started down, clearing insulatedcable portion 55, when the down button 51 is pressed.

The foregoing detailed description is given for clearness ofunderstanding only and no unnecessary limitations are to be understoodtherefrom, as some modifications will be obvious to those skilled in theart.

I claim:

1. In an elevator mechanism: a shaftway; idler sheave means at the topof the shaftway; cable means trained over said idler sheave means; anelevator cage to which the ends of said cable means are secured; aplatform separate from the elevator cage having drive sheave meansaround which the lower end of said cable means is trained where by saidplatform is suspended on said cable means; driving mechanism on theplatform for driving said drive sheave means; and electric control meansfor controlling operation of the driving mechanism.

2. The device of claim 1 in which guide means are provided to laterallyrestrain the cable between the sheave means.

3. The device of claim 1 in which guide roller means on the elevatorcage provide lateral restraint for the cable.

4. In an elevator mechanism: a shaftway; idler sheave means at the topof the shaftway; cable means trained over said idler sheave means; anelevator cage to which the ends of said cable means are secured; aplatform having drive sheave means around which the lower end of saidcable means is trained, said platform being suspended on said cablemeans; driving mechanism on the platform for driving said drive sheavemeans; and electric control means for controlling operation of thedriving mechanism tacting trolley member, and a dielectric sheathsurrounds the upper extremity of said limit wire to break the circuit tothe trolley member and positively limit upward travel of the cage.

6. In an elevator mechanism. a shaftway having vertical guide rails;idler sheave means at the top of the shaft- Way; cable means trainedover said idler sheave means; an elevator cage to which the ends of saidcable means are secured, said cage having guide shoes embracing saidguide rails; a platform having drive sheave means around which the lowerend of said cable means is trained, said platform being suspended onsaid cable means and having guide shoes embracing the guide rails;driving mechanism on the platform for driving said drive sheave means;and

electric control means for controlling the operation of the drivingmechanism from the cage.

7. The device of claim 6 in which safety means are provided to limit theapproach of the cage toward the suspended platform.

Rcferences Cited in the file of this patent UNITED STATES PATENTS216,568 Holske June 17, 1879 515,641 Backman Feb. 27, 1894 516,343 Blakeet al Mar. 13, 1894 1,071,309 Goggin Aug. 26, 1913 2,420,903 Noble May20, 1947 FOREIGN PATENTS 112,293 France May 19, 1876 13,500 GreatBritain Nov. 9, 1888

